Terrestrial vertebrates utilize four main displays in prosematic (i.e., non-verbal) communication. Since the mirror display of the gothic-type squirrel monkey combines features of three of the displays, it has been used in this longterm project for identifying cerebral structures that integrate the somatic and autonomic components of such displays. In earlier work it was shown that the medial segment of the globus pallidus (and its projecting pathways) is a site of convergence of neural systems involved in the evocation and performance of displays. The present project provides the additional information that (1) destruction of the dorsomedial hypothalamic area between the ansa lenticularis of each side practically eliminates the genital autonomic component of the display; (2) the greater part of the ventromedial nucleus of the hypothalamus may be destroyed without affecting the display; (3) coagulation of the ansa lenticularis near its fusion with the thalamic fasciculus results in a transitory elimination of the display, with recovery except for a deficit in vocalization apparently due to destruction of fibers leading to the medial longitudinal fasciculus; and (4) interference with ascending neocerebellar influences does not affect the regular performance of the display. Finally, evidence has accrued that destruction of medial frontal limbic and neocortical areas known to be implicated in vocalization, results in an alteration and marked reduction of the vocal component of the display.